Summary of the iKAGRA Run 14th KAGRA F2F (University of Toyama) Aug 25, 2016 Summary of the iKAGRA Run Yuta Michimura Department of Physics, University of Tokyo based on JGW-T1605101, JGW-T165177 by Y. Michimura JGW-G1605294 by S. Kawamura JGW-G1605296 by K. Kokeyama

iKAGRA Test Run Period - 1st run: Mar 25 9:00 - Mar 31 17:00 (JST) - commissioning break sensitivity and stability improvement - 2nd run: Apr 11 9:00 - Apr 25 17:00 (JST) Purpose - confirm the layout of the vacuum tanks - test control system, data acquisition/transfer/ management, observation shift - get environmental data - obtain experiences of the management and operation of the km-class interferometer

Configuration 3-km Michelson interferometer (instead of Fabry-Perot Michelson) ETMY MCe PR2 MCi MCo Laser 3 km IFI 1064 nm 2 W BS PR3 ETMX GW signal

Simplified Suspensions most of the suspensions were simplified/replaced to meet the deadline from TAMA ETMY Type-Bp’ fixed mirror mount MCe Type-C PR2 MCi MCo Laser IFI BS PR3 ETMX from CLIO

Vacuum central part and both ends were at air (PR2-BS was not even connected) ETMY in vacuum (68 Pa) in vacuum (200 Pa) MCe in vacuum (1.6 Pa) PR2 MCi MCo Laser IFI 1064 nm 2 W BS PR3 ETMX

Environmental Sensors for noise hunting and Newtonian noise estimation seismometer ETMY thermo-hygrometer water gauge / barometer not all of them are shown MCe PR2 MCi MCo Laser IFI BS PR3 ETMX

Controls and Readout reflection port for sensing, ETMs for actuation 3-km RFM network was essential ETMY MCe PR2 MCi MCo Laser IFI BS PR3 ETMX GW Signal

Calibration optical gain calibration using fringes actuator calibration by transfer function measurements calibration lines to monitor TF drift Michelson differential displacement [m] Michelson optical gain 5.7e10 counts/m error signal calibrated in L*h(t) online calib actuator gain monitor signal calibration lines Actuator (klog #1340) ETMX: 1.6e-9 m/counts at DC, f0=0.92 Hz, Q= 5.1 ETMY: 1.0e-9 m/counts at DC, f0=0.94 Hz, Q = 4.6 combined: 2.6e-9 m/counts at DC Filter zero at 0.2,70 Hz pole at 0.02,2000,2000 Hz DC gain 500 UGF servo

Sensitivity limited by seismic noise below ~4 Hz, acoustic/fan noise at around 100 Hz, ADC noise above ~3 kHz ~3e-15 /rtHz @ 100 Hz ~ 4.2 pc for 1.4M-1.4M NS-NS (0.77 pc for 1st run) seismic noise acoustic noise ADC noise plot by T. Shimoda, M. Nakano, Y. Michimura

Duty Factor and Longest Lock 1st run: 85.2 %, 3.6 hours (94.4 %, 12 hours for IMC) 2nd run: 90.4 %, 21.3 hours (98.5 %, 23.5 hours for IMC) 1st run 2nd run data processing by S. Mano plot by Y. Michimura Kumamoto Earthquake, BS went wrong

Data Management real time transfer to ICRR Kashiwa and Osaka City Univ. (~3 sec latency, ~ 200 MB/sec) delayed mirroring at Academia Sinica, Taiwan and KISTI, Daejeon 7.5 TB in total

Hardware Injection right after 2nd iKAGRA run gravitational waveforms of CBC, Supernovae, etc. important end-to-end test

Good Findings The beam went back and forth the 3-km X/Y arms Acquired tidal and environmental sensors data Type-Bp’ was stable enough for 3-km Michelson Controlled the ETMs via 3-km RFM network Observation shift worked well without big trouble Data management also worked very well Many people enjoyed the integration, commissioning, and operation of the large scale interferometer (with some struggle)

Environmental Data tidal distortion temperature / air pressure plot by Y. Shikano seismic stability plot by A. Shoda

Lessons Learned Simple mistakes could happen Careful preparation and planning is important Careful instrumentation is also important (no more loose cables and screws/bolts) Lack of documents / drawings and communication caused troubles More effort on safety needed → extended chief meetings schedule tracking scheme better infrastructure to share drawings safety review

After the Run post-run calibration, transfer function, ADC/DAC and RFM time delay measurements saved and summarized the IFO parameters data processing for analysis and detchar - data correction - offline calibration - search for GW signals - Newtonian noise estimation etc… …… still work in progress publication plan?

Summary iKAGRA Run was successful We had a lot of downgrades to meet the deadline Acquired useful data for bKAGRA Obtained precious lessons for bKAGRA Data processing and characterization still on going